Low-water alarm for steam-boilers and the like.



L AV/ Patented July 27, 1915.

do A R. WOOD.

APPLICATION FILED NOV.6.19I3.

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LOW WATER ALARM FOR STEAM BOILERS AND THE LIKE.

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ETD @TEg AN ROBERT WOOD, on NEW vortx, N. Y, ASSIGNOB TO THE NATHAN MANUFACTURING COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

LOW-WATER ALARM FOR STEAM-BOILERS AND THELIKE.

Application filed November 6, 1913.

To all whom it may concern:

Be it known that I, ROBERT WOOD, a subject of the King of Great Britain and Ireland, residing at 435 East Fourth street,

borough of Brooklyn, city of New York, in

Inthe drawing, 10 represents the side of a steam boiler, secured to which by'any suit able means, as bolts or rivets, (not shown), is a casing 11 adapted to contain the other parts of the device. lVithin the casing is a float-containing chamber 12 closed at the top by a cap 13 and at the bottom by a plug 14L. The cap is secured to, or made integral with, the casing and is provided with a depending neck 140and a central opening, the wall of which is restricted at 15 to form a valveoseat, and which opening leads to a whistle or other device indicated at 16. The

plug 14 is secured to the casing by threads or in any other suitable manner, and is provided with a central recess indicated at 17. The plug may be conveniently made in two parts, a lower part 18 being removably secured to the plug proper by threads or the like. i

At one side, the casing 11 is extended to form a support for a sight glass or water gage, comprising a tube 20, upper and lower tubular holders '21 and 21, and retaining nuts 23.

A passage 25 is made in the casing be tween the upper part of the chamber 12 and the steam space in the boiler, and a similar passage 26 is made between the lower part of the chamber and the water space of the boiler, the latter passage being'preferably made sloping toward the boiler. Each of these passages is controlled by cocks provided with handles indicated at 27 and 28. Apassage 30 is provided from the upper partof the chamber 12 to the upper part Specification of Letters Patent.

Patented July 27, 1915.

Serial N 0. 799,440.

of the water gage and a passage 31 is provided from the lower part of the chamber 12 to the lower part of the water gage. A channel 29 is provided between the passages 25 and 26 and a similar channel 32 between the passages 30 and 31. These channels extend upwardly beyond the passages 25 and 30 and are closed by removable plugs 41 and 42 threaded into the casing 10. A ball valve 33 is adapted to close the upper passage to the water gage and a similar ball valve 34; is adapted to close the lower passage tothe water gage.

Y A float 35 is arranged within the chamber 12. It comprises a hollow vessel having a loose piston-like fit within the chamber and is provided at the bottom with a downwardly projecting extension 36 and at the top with an upwardly projecting tubular extension 37 fitting closely within the downwardly projecting neck140 of the cap 14. It terminates at its upper end in a conical plug valve 38 adapted to engage the seat 15 to control the conduit leading to the whistle 16. The extension 37 is also provided with a series of pockets 40 connected in succession by passages 4C1. -One or more conduits 45 lead from the external surface of the extension 37 to the lowermost pocket so and one or more conduits 46 lead from the uppermost pocket 10 to the valve-controlled passage leading to the whistle.

The operation of the device is as follows: Assuming that thereis. no water and no steam in the boiler the float 35 will, by gravity, drop to the bottomof the chamber 12, its extension 36 fitting within the recess 17 of the plug 14. The passageway 45 of the tubular extension 37 will thus be in com munication with the chamber 12 and passage 25 and air, or other gas, in such chamber and passage will find access through the pockets 4L0 connecting passages 11 up into the passage l6 and through the valve 15 to the conduit leading to the whistle, although,

if the air or gas is not under pressure, the

passageway and the interior of the chamber 12 is cut off and the air can no longer enter the pockets above mentioned or pass to the whistle '16. As the float rises, the conical valve 38 finally engages the seat 15 which controls the passage to the whistle and effectually prevents the entrance of any air or steam through that passage. As the water continues to rise it will also partly, or wholly, fill the water gage and the connnecting passages leading thereto, also the channels 29 and 32, and if it rises far enough will finally flow into the passage 25.

If steam is generated in the boiler the normal water level should be below that of the passageway 25. Supposing that the generation of steam is continued and no fresh water is introduced into the boiler, it is obvious that steam will fill the passage 25 and the upper part of the float chamber 12 and the upper part of the water gage 20 and will always be under pressure in the space above the water level wherever such level may be, and such pressure will also exist throughout the entire apparatus and will not affect the buoyancy of the float 35 because the pressure is equal on all sides of such float. As the water continues to be converted into steam and its level descends, a point is reached where the float 35 descending with the body of water loses its buoyancy and interrupts the contact between the valve 38 and the seat 15 and, continuing to fall, arrives at a point where the passage 4-5 is below the edge of the neck 140 of the cap 13 and steam is permitted to enter such passage, the pockets 40 connected therewith and the passages 46 and to pass through the valve seat 15 into the whistle thereby sounding an alarm to which the at tention of. the engineer is called.

The purpose of the small pockets 40 in the extension 37 and the connecting steam passages is to allow what may be called a preliminary leak of the steam in the boiler into the whistle so that shrill whisperings or low whistlings will take place and can be heard before the fullpressure of the steam can reach the whistle and a premonitory alarm will thus possibly call the attention of the engineer to the low stage of his wa-' ter without the whistle blowing insuch a way as to indicate a more dangerous condition or to alarm others. If the water falls to such a point that its level is coincident with the upper part of the passages 26 and 31 the pressure of the steam from above will blow all of the water out of these passages back into the boiler and cause a sudden drop of the float35 to occur, and the full force of the steam will then suddenly be exerted upon the whistle and create a loud alarm.

Should the steam suddenly enter the wa ter gage, or should the pressure in the gage suddenly be increased or the amount of heat conducted to the walls of the water gage be suddenly increased, or for any other reason should the glass in the water gage be broken, no harm will result therefrom (except the expense of replacing the glass), because the two ball valves 33 and 3-1 will close the upper and lower passages leading to the gage and will prevent the escape of any serious amount of steam from the casing.

It should be noted'that the parts of the device are few and simple.

There is nothing to getout of order or to prevent the prompt working of the parts.

The device requires no attention and is always ready for service.

What I claim is:

1. In a low water alarm for steam boilers and the like, a casing inclosing a float chamher and having an alarm supply opening provided with an internal valve seat, a float operating in the float chamber, and a valve device controlling the opening and including an extension operating in said opening and having a valve movable into and out of coac'tion with the seat, said extension having a passage provided with an outlet port that opens into said opening in advance ofthe valve seat and also having an inlet port that is located in the opening when the valve is initially unseated tov permit leakage past the valve, said inlet port being movable out of the opening to allow a free flow through the passage and past the valve seat.

2. In a low water alarm for steam boilers and the like, a casing inclosing a float cham ber and having an alarm supply opening provided with an internal valve seat, a float operating in the float chamber, and a valve device controlling the opening and including sides of the extension, and aninlet port that is located in the opening when the valve is closed, said pockets and port permitting a slight leakage through the extension past the valve when the said valve is initially unseated and said inlet port being movable out of the opening to allow a free flow through the passage and valve.

3. In a low water alarm for steam boilers and the like, a casing inclosing a float chamber having an alarm supply opening in its top provided with a contraction forming an internal valve seat, and a float operating in thefl'oat chamber and having'an upward extension projecting into the opening and terminating in a plug valve that'cooperates with the seat, said extension having a longitudinal passage therein that opens in advance of the valve and is provided with also plurality of pockets opening through the sides of the extension and disposed within the opening.

4:. In a low Water alarm for steam boilers and the like, the combination with a casing inclosing a float chamber, of a float in the chamber, an alarm controlled by the float, a gage having upper and, lower passages communicating respectively with the upper and lower portions of the float chamber, a substantially upright passage connecting said upper and lower passages, and automatic valves for the gage, one of said valves being disposed at the juncture of the substantially upright passage with one of the connecting passages.

5. In a low water alarm for steam boilers, and the like, a casing inclosing a float chamber, means for connecting the upper and lower portions of the casing respectively to the water and steam portions of a boiler, an

Copies of this patent may be obtained forfive cents each, by addressing the alarm supply opening communicating with the upper portion of the chamber and having an internal valve seat spaced from its inlet end, a float in the chamber, and a valve device operated by the float and operating in the alarm supply opening in advance of the valve seat, said valve device comprising a terminal valve cooperating with the seat, a plurality of pockets formed in the device, and an inlet port formed in the device and movable into and out of the alarm supply opening, said port having communication with the different pockets and opening through the inner end of the valve device at one side of the valve.

In testimony whereof I affix my signature in presence of two witnesses.

ROBERT WOOD. Witnesses:

MARY H. LEwis, HELEN V. FITZPATRIOK.

Commissioner of Patents,

Washington, D. G. 

